report_card

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

With no annotations, the description carries the full burden, and it discloses meaningful behavior: the data source ('Read from what the agents did, not what they said') and the return format ('A Markdown table'). It omits cost/permission/limits detail, but for a reporting tool those are lower-stakes than the output-shape disclosure it does provide.

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 lead sentence front-loads what the tool is, but the middle collapses a long metric list into one winding clause ('how many that changed code were tested after the last change and passed...'), which is dense and partly redundant. The closing `project` tip is worth its space; the enumeration is only borderline.

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 read-only report tool with full schema coverage and no output schema, the description explains both what the report contains and its Markdown return format, which is what an agent needs. Nothing critical is missing, though it could state that it is a safe, non-mutating read.

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 both `since` and `project` are already documented with formats and defaults. The description's 'Pass `project` for one project' and default-period note merely restate schema content, adding no syntax or edge-case meaning beyond it.

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 names a concrete artifact ('a report card comparing the agents side by side over a period') and enumerates the metrics it contains, so the resource and scope are unmistakable. It does not, however, explicitly distinguish itself from near-neighbors like 'recap', 'today' or 'brief', which a reader must infer from the metric 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?

It states the default window ('last 7 days, every project') and how to narrow scope ('Pass `project` for one project'), which implies typical usage. There is no explicit when-to-use-this-vs-alternatives guidance, so the agent gets context but not routing rules against the sibling reporting tools.

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