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

Annotations already declare readOnly and closed-world, but the description adds substantial behavior beyond them: the precise payload fields, the explicit negative guarantees (never returns documents or payment details, never accepts or reads documents), and where the write-type actions actually live. Those negatives are exactly the kind of boundary an agent needs to avoid misrouting a request.

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 usage condition, then a compact enumeration of return contents and a negative-scope sentence. The enumerated field list is long but each item carries information; structure is clear and free of filler.

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?

A single-parameter read tool with no output schema, and the description compensates by enumerating what comes back and what does not. Nothing an agent needs in order to decide to call it or to interpret the result is missing.

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 is a single optional parameter and the schema description already covers it at 100%, including the default to the most recently updated application. The description adds no additional syntax or format guidance, 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 clear resource and scope: status of the signed-in user's own application, plus an enumeration of the exact fields returned (stage, next steps with link, UGE registration number and filing date, last UGE status, receipt download location). That is enough to distinguish it from a generic listing tool, though no sibling (e.g. my_applications) is named for contrast.

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?

"Use only when the signed-in user asks about the status of their own application" gives an explicit triggering condition, and the closing sentence implicitly rules out out-of-scope actions (uploads, payment, power of attorney) by redirecting them to spainvisasubmit.com. Alternatives among the sibling tools are not named, so it stops short of a full when/when-not/alternative statement.

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