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

Annotations already declare readOnly=false, idempotent=true and destructive=false, so the safety profile is covered without the description. The description adds only the closed set of valid status strings; it says nothing about what happens on an invalid or disallowed transition, whether a non-existent projectName causes creation, or what the call returns. With annotations carrying the load, this is a modest but real contribution.

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 with zero filler; the allowed values are listed inline where the agent needs them. It is appropriately sized, though it spends its only clause on information the schema already carries.

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 simple three-parameter mutation with full schema coverage, no output schema, and annotations covering safety and idempotency, the description is close to sufficient. However, an agent still cannot tell whether the projectName path resolves only existing projects or can create one, nor what error behavior to expect on an invalid status.

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 the schema already documents all three parameters including the 'used if projectId is not given' fallback for projectName. The description's enumeration of statuses duplicates the schema's own status description, adding no syntax, casing, or precedence detail beyond it. 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?

The description names a specific verb ('changes the status') and a specific resource ('of a project'), and enumerates the allowed values, which distinguishes it from the similarly-named sibling updateProject (general field update) and from updateTaskStatus/updateQuoteStatus by resource. It stops short of explicitly stating the boundary versus updateProject, so it is clear but not fully sibling-differentiated.

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?

Usage is only implied: the agent can infer this is the tool for status transitions on a project, but there is no explicit when-to-use versus updateProject, no statement about whether other fields can be changed here, and no preconditions (e.g. permissions or allowed transitions). Adequate minimum-viable guidance, with clear gaps.

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