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

Annotations already cover the read-only, open-world nature, but the description adds two real behavioral traits: the shape of results (hashtags carry post counts, places carry location ids) and an explicit cost of 1 credit, which is quota information not available in the structured fields.

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?

Very short and front-loaded with purpose, with cost isolated at the end. The second sentence partially restates the first, which is minor redundancy but not harmful.

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?

With no output schema, the description usefully sketches the return shape (accounts, hashtags with counts, places with ids), which is the key missing structured information. Pagination or result-count limits are not addressed, leaving a small gap.

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?

There is a single parameter with 100% schema coverage, including a description, maxLength, and example, so the schema already carries the meaning. The description adds nothing about the query syntax or matching behavior, making 3 the baseline.

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 states a specific verb (search) and the exact resource types returned (accounts, hashtags, places), which distinguishes it from instagram_audio_search and instagram_reels_search. It stops short of naming those siblings explicitly, so an agent must infer the boundary from the resource list.

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?

Usage is only implied: the three result categories hint that this is the discovery entry point before using instagram_username, instagram_hashtag, or instagram_place for details. There is no explicit when-to-use statement or named alternative.

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