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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=true, so the safety profile is covered. The description adds the important scoping fact that status is mutated elsewhere, but it never says whether omitted parameters leave fields unchanged (all 10 params are optional) or whether permissions are required — the key behavioral question for a partial-update tool.

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 short sentences with zero filler; the field scope is front-loaded and the sibling exclusion is stated last where it is most actionable. Nothing repeats the annotations or title verbatim.

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 10-parameter, zero-required mutation tool, the definition omits two things an agent needs: how the target project is resolved (projectId vs projectName search) and whether unspecified fields are preserved. Annotations and the schema carry the rest, and there is no output schema to explain, but these gaps are material.

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 in the schema, and the description's field list largely restates it. It adds no guidance on the ambiguous identification pair, projectId versus projectName (a name search), so the baseline 3 holds.

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 ('Updates an existing project') and enumerates the mutable fields (name, customer, address, description, budget, dates, color). It also explicitly separates itself from the status-mutating sibling with 'The status has its own tool.'

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 final sentence routes the agent away from this tool for status changes and toward the dedicated sibling, which is a genuine use/don't-use boundary. It does not clarify when to prefer saveProject or createProject over this, so the guidance is clear but not exhaustive.

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