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

Annotations already cover the mutation profile (readOnly=false, idempotent=false, destructive=false, openWorld=true), but the description adds the non-obvious operational facts that this sends real invitations and can consume credits. It does not say what happens on partial failure — e.g. whether some invitations are sent if a later signer fails validation.

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?

Three sentences with the core action front-loaded, followed by prerequisites and then the cost caveat. No filler, and each sentence carries a distinct piece of 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 9-parameter mutation tool with no output schema, the description covers the action, prerequisites, and credit implications, which is most of what an agent needs. It stops short of describing the result (document ID vs. invitation status) or failure behavior when a role has no matching signer.

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 every parameter including the nested signer fields is already documented in the schema. The description restates the ID-or-name/email alternative and the one-signer-per-role rule but adds no syntax, ordering, or constraint detail 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 combination — generate a document from a saved template and invite one signer per role — which separates it from assinafy_send_pdf_for_signature (arbitrary PDF) and assinafy_create_assignment. It never names those siblings outright, so an agent must infer the boundary from the 'saved template' phrasing.

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?

Explicitly routes the agent to two prerequisite tools: assinafy_list_templates to discover roles and assinafy_validate_fields to check editor_fields values before calling. It gives clear context but offers no when-not guidance distinguishing it from assinafy_send_pdf_for_signature or assinafy_create_assignment.

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