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

Annotations already declare readOnlyHint=false, destructiveHint=true and openWorldHint=false, so the safety profile is largely covered. The description adds real context beyond that: the partial-update contract (only send arguments whose value should change) and the immutability of name/title fields for internal signatories. It doesn't spell out reversibility or the effect of a party move, keeping it at a 4.

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?

Front-loaded with the core action, then bulleted conditions, then the identification/optionality rule. Every sentence carries information an agent needs and there is no padding.

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?

Given a destructive write tool with 7 parameters, 100% schema coverage and an existing output schema, the description supplies the missing pieces: identification requirements, partial-update behavior, and the internal-signatory constraint. Nothing an agent needs in order to call this correctly is absent.

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 a baseline of 3 applies. The description earns above that by stating which two parameters identify the signatory, that every other argument is optional and only needed when its value should change, and by restating the internal-signatory restriction on name/title fields — semantics the schema's null-typed properties do not convey.

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 opens with a specific verb+resource pair ('Edit the details of a document signatory') and enumerates the exact editable fields (name, title, mobile phone, party assignment). It implicitly separates itself from create/delete signatory siblings but never names an alternative tool, so it stops short of full sibling differentiation.

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?

An explicit 'Use this tool when' block gives two concrete triggering conditions (field changes before signing starts, moving a signatory between parties), which is clear context. However, there is no explicit 'when not to use' clause and no named alternative (e.g. update-document-party), so it falls short of a 5.

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