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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds nothing beyond that - no mention of required permissions, whether an existing party is replaced, or side effects - so it provides minimal added behavioral context.

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?

The first sentence is efficient, but the 'Use this tool when' bullet is pure tautological filler that consumes space without adding information. Under-specification dressed as structure rather than genuine conciseness.

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?

An output schema exists, so return values need not be explained, and annotations cover the mutation safety profile. However, for a create operation with several close siblings, the description leaves the agent without guidance on prerequisites or alternative tools, so it is only minimally complete.

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 six parameters including the enum and mutual-exclusion rules. The description adds no parameter meaning at all, making the baseline 3 correct.

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 opening sentence gives a clear verb+resource ('Adds a new party to a document'), which an agent can act on. However, it does not differentiate from close siblings like create-template-party, update-document-party, or create-document-signatory, so it falls short of a 5.

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 'Use this tool when' section is circular: 'You need to add a new party to a document' simply restates the purpose. No alternative tool is named, no exclusions, and no condition that would route the agent between this and create-template-party or update-document-party.

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