file_search

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

With no annotations, the description carries the behavioral disclosure burden. It discloses case-insensitivity, literal (non-regex) matching, recursive directory behavior, and return of structured hits with context lines. It could mention stop-after-max behavior or permissions, but the disclosed traits cover the core operation well.

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 sentences with no fluff. The primary action and scope are front-loaded, and each sentence adds distinct value: search behavior, return shape, case sensitivity, and alternative tool routing.

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 moderately complex search tool with no output schema, it explains the result type ('structured hits with surrounding context lines') and all key selector behaviors. It is slightly vague about the exact output format and edge cases, but the combination of description and fully documented schema is adequate for correct invocation.

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 description coverage is 100%, so the schema already documents all five parameters thoroughly. The description adds behavioral context like case-insensitivity and literal matching, but it does not add substantial parameter-level meaning beyond what the schema provides.

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 uses a specific verb ('Search') and identifies the exact resource scope: a literal string in a file or recursively in a directory. It also distinguishes itself from shell_exec by explicitly punting regex searches to that sibling, so agents can disambiguate without reading schemas.

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?

It states when to use this tool ('Replaces grep -n') and explicitly names the alternative for a different case ('For regex searches, use shell_exec'). This gives clear selection criteria among the sibling tools.

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