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

Annotations already declare readOnly, idempotent and closed-world, so the safety profile needs no restating. The description adds real value beyond them: the 25-result cap, that pricing is 'as the maker states it' (no normalization), and that each hit carries a listing URL and a plain data-locality note.

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?

Three tightly written sentences, with the core action and filter scope front-loaded before return-shape details. Minor redundancy between the filter list mentioning 'data-locality (runs_locally)' and the later data_locality sentence, but nothing extraneous.

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 carries the burden of describing results, and it does: cap of 25, pricing caveat, listing URL, and the four data_locality states. Adequate for an agent to act on results; only slight gaps around ranking/relevance behavior.

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?

Schema coverage is 100%, so all six parameters are already documented, including the runs_locally enum semantics and the limit default. The description only re-lists the filter names and restates data_locality values, adding little beyond what the schema says. Baseline 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?

States a specific verb and resource ('Search the AgentScout directory of AI agent tools and MCP servers') with keyword-plus-filter scope. This implicitly separates it from get_tool (single lookup) and list_categories (taxonomy), though it never names those siblings explicitly.

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 implied by the verb 'search' and the note that the query is 'optional if a filter is set', but there is no explicit when-to-use versus best_for_task or get_tool. It never tells the agent when NOT to use this tool or which sibling to prefer.

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