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

Annotations already declare the safety profile (not read-only, not destructive, not idempotent, closed-world), so the description's main value-add is disclosing the authorization requirements: logins:write scope plus editor role. What it omits is failure behavior — duplicate handling, validation errors, and what a non-editor caller sees — but the annotations lower the bar here.

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?

Two short sentences, zero filler, with the core action front-loaded and the access constraint trailing where it belongs. Every clause carries 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 6-parameter mutation with no output schema, the definition covers the action and the permission gate but says nothing about the result (presumably the created login object) or about duplicate/conflict behavior on a non-idempotent create. Adequate, but an agent would still have to guess at error semantics.

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 only 33%, so the description must compensate, and it largely does by naming url, username, notes, password, and the project container, leaving only `name` uncovered (which the schema itself documents as derived from URL when omitted). Format details such as what constitutes a valid project slug or URL form are still left to 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 opens with a specific verb and resource ("Save a password") and enumerates the payload fields (URL, username, notes) plus the containing resource (a project). It is clearly a creation operation, but it never names the nearby alternatives (update_login, create_secret) that an agent must choose between.

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?

Usage is only implied: the verb "Save" and the required `project`/`password` inputs suggest a new-record creation, and the prerequisite line ("Requires logins:write and the editor role") gives a real gate. There is no explicit statement about when to use this instead of update_login for an existing entry, nor what happens if a login for that URL/username already exists.

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