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

Beyond the annotations (destructive/idempotent/non-read-only), it discloses the manual-evidence caveat, the consent and tier requirements, the idempotency-key requirement, and optimistic-concurrency guidance ('use its current revision'). It adds real behavioral context, though it doesn't say precisely what state is mutated on an existing record.

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 dense, front-loaded sentences: purpose first, then requirements, then the concurrency rule. Every sentence carries information, though the requirements sentence packs several constraints into one clause chain.

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 an output schema present, return values need no explanation, and the description covers preconditions, idempotency, and concurrency for a destructive mutation. It stops short of explaining what target_id designates or how a wrong expected_version is surfaced, leaving minor gaps.

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%, so the description bears full burden. It clarifies three of the four concepts -- idempotency_key, confirmation_token ('exact-intent confirmation'), and expected_version ('current revision') -- but leaves project_id, target_id, and the evidence payload unaddressed, so it only partially compensates.

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 specific verb+resource ('Record manual completion evidence for one exact scheduled occurrence') and immediately bounds it with 'this does not prove provider execution,' which separates it from execute_action and prepare_manual_completion. An agent can distinguish the intent without opening the 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?

It states clear preconditions (Startup tier, read+write consent, idempotency key, exact-intent confirmation) and an operating rule ('read current state and use its current revision'). It does not explicitly route between this tool and nearby siblings like prepare_manual_completion or execute_action, so no exclusion guidance is given.

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