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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), and the description adds real behavior on top: the default for startedAt (counts backwards from now) and the default for billable (true). It stops short of warning that repeated calls create separate entries, which is the main hazard implied by idempotentHint=false.

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?

Front-loaded with the core purpose and sibling contrast before parameters, and the sentences about record_run and billable each add distinct decision value. The restated 1–1440 range duplicates the schema bounds, the one clearly redundant fragment.

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 5-parameter mutation tool with no output schema, the description covers defaults, constraints, and the main misuse case (deriving time from record_run). It leaves the `note` parameter unaddressed and says nothing about what the created entry looks like or whether it can be edited afterwards.

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 only 20%, so the description has to carry the load, and it mostly does: it explains minutes bounds, startedAt as epoch ms with a backfill default, and the meaning/semantics of billable. Only `note` is left completely undefined, which is a small but real gap given the low coverage.

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 verb+resource ("Imputa tiempo a una issue") and immediately scopes it with "SIN reloj", which separates it from start_timer/stop_timer siblings. It also explicitly rules out record_run as an alternative source of time, so an agent can place the tool without opening any schema.

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?

Gives explicit when-to-use reasoning ("es la forma normal de que un agente registre lo que ha tardado, porque al terminar ya lo sabe") and an explicit when-not ("No deduzcas el tiempo de record_run") with the rationale about build waits. It also gives a decision rule for the billable flag (internal, non-client work).

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