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

Annotations already establish read-only, idempotent, non-destructive behavior, but the description adds genuinely non-derivable context: private blockers stay private and only a coarse signal is emitted, with an explicit confidentiality boundary. It does not describe response shape or failure modes, so it is not a 5.

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 short sentences, front-loaded with the core action and scope, with no filler. The repeated 'never ... and never' construction and title restatement are mildly redundant but not bloated.

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 privacy-sensitive tool whose output schema already covers return values, the description adequately covers the confidentiality contract but omits any parameter-level guidance despite 0% schema coverage and a sensitive safetySignal enum. An agent can call it, but not confidently for the non-required fields.

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 0% for all four parameters, so the description must carry the burden and largely does not: privateBlockers, safetySignal, and desiredFocus are never explained. Worse, the coarse outputs it cites ('available/reduced/unavailable') do not match the selfReportedCapacity enum, which uses 'recovery_needed' and 'paused' instead of 'unavailable'.

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 verb and resource ('capacity check-in') and explains the output contract ('emits only coarse available/reduced/unavailable for a shared work graph'). This clearly distinguishes it from generic work-status siblings, but it never names or contrasts a specific alternative tool, so it falls short of a 5.

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?

There is a strong exclusion ('never fitness-for-duty', never exposed to employer/public board), but no positive when-to-use guidance or named alternatives (e.g., my_work, work_status) that would tell an agent when to invoke this versus other status tools. The one boundary does not compensate for the missing invocation context.

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