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

With no annotations, the description carries the full burden, and it does add some context: the result is a 'receipt for progress, never a grade,' and it returns a 're-checkable seal.' That conveys intent and non-evaluative nature. But it omits side effects, whether the seal persists, idempotency, or permission needs.

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?

One compact sentence plus a trailing clause, with the category tag front-loaded. No padding, though the density of unexplained jargon ('seal', 'WALK') slightly hurts scannability.

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 1-param, no-annotation, no-output-schema mutation tool, the description is thin: it never explains what a 'unit' string should contain, how the seal is produced, or how it is verified. The return value is alluded to ('re-checkable seal') but not elaborated despite there being no output schema.

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 coverage is 0% and the sole parameter 'completed' takes an array of strings (up to 200), yet the description describes an 'HONEST INTEGER count.' This mismatched mental model of the input could actively mislead the agent into passing a number rather than a list of unit identifiers.

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?

States a specific action (seal a count of completed units) and frames it as a progress receipt, which is more than a restatement of the name. However, 'seal' is unexplained jargon and the description never distinguishes this tool from the many other coach_* siblings (coach_next, coach_unit, coach_recommend), leaving the agent to guess where it fits.

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 '[WALK · internal]' tag hints this is an internal/companion action, but there is no explicit when-to-use, when-not-to-use, or named alternative among the coach_* family. The agent gets no routing guidance.

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