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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=false. The description adds genuinely useful auth context ('Requires project_phase_categories:write scope'), but it omits what the non-idempotent behavior implies (duplicate categories on repeated calls) and what the response returns.

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 action statement is front-loaded and the permission requirement follows immediately. Nothing could be removed 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 simple three-parameter create tool whose safety profile is fully covered by annotations and whose params are fully documented in the schema, this is close to sufficient. It stops short of 5 only because it says nothing about duplicate-name handling for a non-idempotent create.

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% and all three parameters carry inline descriptions with constraints (maxLength, min/max, examples), so the description is not required to compensate. It adds no syntax or ordering guidance beyond the schema, 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 and resource ('Create a new project phase category'), which cleanly separates it from sibling creators like create_project_phase and create_cost_category. It does not, however, explain how the 'category' groups phases, which would help an agent distinguish it from create_project_phase.

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?

No when-to-use or when-not-to-use guidance is given, and no alternative sibling is named. The only conditional information is the required scope, which is a permission prerequisite rather than usage direction.

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