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

Annotations only declare destructiveHint=true, so the description earns real credit for clarifying 'Only the fields you pass change' — this tells the agent the mutation is a partial update and that unmentioned fields are not wiped, directly tempering the destructive hint. It still omits how to clear a field, auth/permission requirements, and error or conflict behavior, so it is not fully transparent.

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 tight sentences with zero filler; the mutation scope is front-loaded and the partial-update semantics and GraphQL mapping follow compactly. Every clause carries 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 mutation tool with no output schema, the definition covers the mutable surface and partial-update semantics well, which is most of what an agent needs. Remaining gaps are secondary: no guidance on nulling out fields despite destructiveHint, and no mention of permission requirements or failure modes.

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 all eight parameters (including the required client_id and formats like E.164 phone and YYYY-MM-DD dob) are already documented in the schema. The description merely restates the mutable field list in prose without adding format, constraint, or edge-case 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?

Names a specific verb+resource ('Change a client') and enumerates exactly which attributes are mutable (name, email, mobile phone, DOB, pronoun, external id), plus the GraphQL mutation it maps to. This is unambiguously distinct from sibling tools like boulevard_create_client or boulevard_get_client.

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 implied rather than stated: an agent can infer this is the mutation to use when altering an existing client, but the description names no alternatives, no prerequisites, and no when-not-to-use condition. The partial-update note hints at usage but is really behavioral, not routing guidance.

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