instagram_search_expand

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context: it emphasizes high precision ('far better precision than any search box'), clarifies that it operates on a pool (implying state expansion), and states it returns api_calls and errors, hinting at possible rate-limit or error behavior. This goes beyond what annotations state without contradicting them.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is somewhat verbose—it opens with a marketing-style claim about being the 'highest-yield stage'—but every sentence serves either to define purpose, guide usage, or document parameters/returns. It is front-loaded with the core purpose, and the Args/Returns blocks are clearly separated. It could be tightened, but it remains effective and readable for its length.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with 3 parameters, an output schema, and annotations covering safety, the description is thorough. It explains the operational context (when to run it relative to the search pipeline), what it does, and what it returns (seeds_used, added, pool_size, api_calls, errors, next_step). It does not mention prerequisites like needing an active search_id, but that is implied and not critical. Overall it gives an agent everything needed to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 100% coverage, with all three parameters described. The description's Args section essentially paraphrases the schema (e.g., 'Explicit seeds, overriding the pool's own ranking' vs. schema's 'Chain off these handles instead of picking from the pool'). It adds minimal new meaning beyond the schema, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Grow the pool by asking Instagram for accounts similar to your best ones.' It immediately conveys that this tool expands a candidate pool via Instagram's similarity graph, and explicitly contrasts it with keyword probes, distinguishing it from sibling search tools like instagram_search_start and instagram_search_enrich. The purpose is unmistakable and operationally clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit when-to-use guidance: 'Run it once the pool has a few good accounts in it, and again after scoring, when the seeds it picks are proven matches rather than guesses.' It also frames the tool's position relative to other search stages ('Keyword probes find a foothold; this walks Instagram's own similarity graph outward from it'). It does not name specific sibling tools, but the context is clear enough for an agent to select it appropriately within the search workflow.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.