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

Annotations already declare the mutation profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), yet the description adds real traits beyond them: token values are encrypted and never stored in cleartext, cookies are merged into the bound identity without altering its config, and a 419 response signals the percent-encoded-cookie/XSRF failure mode. It stops short of stating permission requirements or reversibility of an auth change, so not a full 5.

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 verb and resource, and every clause carries information (payload shapes, merge semantics, error diagnosis). However it is a single dense block heavy with parentheticals and semicolons, which trades some scannability for completeness.

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 no-required-param mutation with nested objects and no output schema, the description supplies most of what an agent needs: identity selection, per-type payloads, the cookie-refresh mode, and the 419 failure hint. It omits how existing auth is replaced/conflicted and any permission or return-value expectation, leaving minor gaps.

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 coverage is 100%, but the description goes far beyond the schema by mapping auth type → required payload shape (bearer/basic → token; api_key → token + header_name in a HEADER; query → token + param_name in the QUERY STRING; custom_headers → headers object; browser_identity → identity_id/identity_name + extract) and by documenting value_format:'urlencoded' for percent-encoded cookies. The schema's generic field list does not convey this type-to-field mapping.

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+resource ('Set or update the authentication on an HTTP-API integration') and immediately scopes it against alternatives by noting oauth2/service_account use the REST settings flow instead. An agent can distinguish this from integrations_list, integrations_set_realtime, and the REST settings path without opening any schema.

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 covers when to use it (identify by integration_id or base_url, pass auth), when not to (oauth2/service_account → other flow), and a special alternative mode: OMIT auth and pass cookies/local_storage to only refresh a browser_identity session without touching its config. The when/when-not/alternative structure is fully present.

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