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

Annotations already declare destructiveHint=true, so the mutating nature is known. Beyond that the description adds nothing behavioral — no statement of whether this is a partial or full replacement (the 'PUT /v1/tasks/{id}' notation conventionally suggests full replacement while every field except id is optional), no permission requirements, and no note that omitted fields may be cleared.

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?

A single front-loaded sentence naming the operations, plus the endpoint as a compact suffix. Every clause earns its place with no filler.

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 7-parameter mutation tool with low schema coverage and no output schema, the description covers the main actions but omits partial-vs-full update semantics, what happens on success, and one parameter (personId). Adequate to invoke, not sufficient to invoke confidently.

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 29%, so the description has to carry weight — and it largely does by mapping actions to parameters (isCompleted, name, type, assignedTo/assignedUserId). It does not mention personId or assignedTo vs assignedUserId disambiguation, so the compensation is incomplete rather than thorough.

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 (update) and resource (task) and enumerates the concrete update operations — mark complete, rename, retype, reassign — which maps directly onto the schema's optional fields. Sibling differentiation from fub_create_task and fub_list_tasks is implicit in the verb, not explicit, 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?

The listed operations ('mark it complete, rename, retype or reassign') imply the scenarios the tool covers, which is useful. But there is no explicit when-to-use guidance, no exclusions, and no routing to alternatives such as create_task for new tasks or list_tasks for reads.

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