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

Annotations already mark this as read-only, idempotent, and non-destructive, and the description adds useful behavioral context by listing the exact sections produced (Purpose, Business Context, Data Fields, Business Rules, Related Objects, Security, Open Questions). It clearly signals that the tool composes a document rather than modifying system state.

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 description is well organized with WHEN, function statement, generated sections, and triggers. It is slightly redundant because trigger phrases in the WHEN line overlap with the Triggers list, but it is still compact, scannable, and every section adds useful 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 3-parameter tool with no output schema, the description covers the main requirements: what it generates, when to use it, when not to use it, and the trigger phrases. It does not explicitly describe the output format or return value, but 'structured FDD ready for review and sign-off' provides sufficient expectation for the agent.

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 baseline is 3. The description does not add much beyond the schema for parameters, though the mention of 'with resolved labels' gives a small hint about how `objectName` affects the output. The optional `context` and `language` are already well documented in the schema.

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 identifies a specific verb and resource: 'WHEN: user asks to write or generate a Functional Design Document' and 'Produces a structured FDD'. It also explicitly distinguishes itself from `get_object_details`, which is for developer technical docs, so an agent can select the right tool without ambiguity.

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 description provides explicit WHEN conditions, a clear NOT case, names the alternative tool (`get_object_details`), and lists concrete trigger phrases in multiple languages. This gives the agent strong, actionable guidance on when to use this tool versus siblings.

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