file_brief

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

With no annotations, the description carries the burden of behavioral disclosure. It explains what the tool returns, that the result is distilled rather than exhaustive, and that scope controls whose sessions are searched. It does not discuss authentication, rate limits, or edge cases, but for a read-only informational tool the disclosed behavior is sufficient.

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 compact, front-loaded with the tool's purpose, and every sentence contributes either core behavior, usage context, or parameter explanation. There is no fluff or repetition.

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?

The description covers purpose, when to use it, what the output contains, and the main scope parameter, which is adequate for a simple read-only tool with an output schema. The only minor gap is limit semantics and edge cases like files with no prior sessions.

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?

Input schema description coverage is 0%, so the description must compensate. It explains the scope parameter well: 'mine', 'team', 'org', and the omission behavior. It also maps path to the file whose history is briefed. However, the limit parameter has no explanation of how it caps the brief, and path format is not further specified.

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 action and object: 'Return a distilled brief of prior sessions that touched a file', and specifies the returned fields (who, when, a short highlight). It is clearly about file history rather than session text search or session summarization, though it does not explicitly name sibling tools for contrast.

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: 'Use before a non-trivial edit to a file you don't already have context on'. It also provides a when-not-to-use rule: 'Do not call this for every file you read; only when prior history is actually likely to change your approach.' This is strong usage routing even without naming sibling alternatives.

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