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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered structurally. The description adds the non-obvious behavioral fact that this is a sparse/partial update, which meaningfully softens the destructive hint; what it does not explain is what the destructive flag actually implies here (e.g., whether omitted fields can 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?

Three short sentences with the operation type front-loaded as "WRITE", zero filler, and the partial-update rule placed before the endpoint. Nothing can be cut without losing information.

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 with no output schema, the description says nothing about what comes back or how to confirm the change succeeded, and it does not address the destructiveHint meaning. Params and safety hints are otherwise well covered, so this is adequate but with a real gap around result handling.

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%, so every parameter is already documented, including finished=true/false and fuzzy semantics. The description's example mappings (finished = true to mark done) repeat what the schema says, adding no new meaning, so the baseline 3 applies.

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 ("change a task") plus the resource and gives concrete examples of what changing means (mark done, rename, reschedule), which is enough to separate it from create_task and get_task without opening a schema. The endpoint (PUT /tasks/{id}) reinforces the update-only scope.

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?

"Only the fields you give are sent" implies partial-update usage, which is useful, but there is no explicit statement of when to use this versus create_task or get_task, and no stated prerequisite beyond the required task_id in the schema. Usage is implied rather than guided.

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