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

It explains the permanent vs session-only behavior and that calling with no args returns a link. It also clarifies the token as a JWT. This goes beyond the annotations (which only indicate idempotent, non-destructive, not read-only) and provides useful 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 description is a single, elongated sentence with multiple semicolons, combining several distinct pieces of information. It's not overly verbose but could benefit from clearer sentence breaks. It still covers essential points efficiently.

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?

Given the single parameter, there is no output schema, and the description covers both invocation modes, the purpose of the token, and the no-args behavior. It is sufficiently complete for an agent to use the tool correctly.

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?

There's zero schema coverage, so the description must define the 'token' parameter. It does so, calling it a JWT to be pasted, and explains the effect of providing or omitting it (session login vs retrieving link). This adequately compensates for the missing schema documentation.

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 clearly states it is for authentication: 'log in in the browser, copy the access token'. This is a specific verb and resource, and it distinguishes this tool from its siblings (which are unrelated).

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?

It gives explicit best practice ('Best: add it to this server's config as a header') and two distinct invocation modes: with a token for session-only login, or with no args to get the link. It doesn't explicitly mention when not to use it, but there are no similar sibling tools to confuse it with.

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