build_timing_report

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

With no annotations, the description carries full responsibility. It discloses that output is ranked, slow, and tied to a previous build_run, which is useful. However, it doesn't mention side effects (likely none), permissions, or what happens if no previous build exists. Adequate but not rich.

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?

A single, front-loaded sentence that conveys all essential information without unnecessary words. It is perfectly scannable and immediately understandable.

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 simple tool with one optional parameter and no output schema, the description covers the core purpose well. However, it could specify the return format (e.g., array of objects with timings) to fully equip the agent, as the tool appears to generate a report.

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% with the buildId parameter already documented as defaulting to the most recent build_run. The description's language 'previous build_run call' aligns with this but adds no new insight beyond the schema. Baseline 3 is appropriate.

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 'Return' and clearly identifies the resource ('ranked slow build task categories/functions/expressions') and context ('for a previous build_run call'). It effectively differentiates itself from sibling tools like build_run or cache_inspect by focusing on report generation.

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 phrase 'for a previous build_run call' implies usage after build_run, but there is no explicit guidance on when to choose this over alternatives or any exclusion criteria. Sibling tools are distinct enough that usage is inferable, but the description doesn't make it explicit.

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