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

Annotations already declare this as a non-read-only, non-idempotent, non-destructive write, so the safety profile is covered. The description adds two useful facts beyond them: the los_measurements:write scope requirement and the FK-resolution precondition. However, it says nothing about whether re-posting the same period conflicts or what happens on failure, so it is modest added value rather than rich disclosure.

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?

Two tight sentences with the action, then the authorization and prerequisite, in that order. Zero filler and every clause is actionable.

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?

With no output schema, the description reasonably covers the prerequisites and permissions for a 7-parameter write tool, and the schema documents every field. The main gap is the absence of any statement about duplicate measurements for the same period or the response shape, which matters given idempotentHint=false.

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% across all 7 params, including enum values for period_type and ISO 8601 formats, so the schema carries the semantics. The description mentions only los_measure_id resolution and adds no meaning for actual_value, period_type, is_auto, or notes. Baseline 3 is correct.

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 and resource: 'Record a new LoS measurement value.' An agent can distinguish it from create_los_measure (the measure definition) and create_los_measurement's list/get/update/delete siblings by the object being recorded. It does not explicitly contrast itself with those siblings, so it stops 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?

Gives a concrete precondition and route: 'Resolve los_measure_id first via list_los_measures,' which names the exact sibling to call beforehand. It also states the required scope. No when-not-to-use guidance or mention of duplicate-period behavior, so not a 5.

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