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

Annotations already establish a safe, closed-world read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), and the description adds real value on top: it declares the tool never accepts or reads documents and redirects mutating actions to the website. This prevents an agent from trying to attach files or perform payments through it. It stops short of describing result ordering or empty-account behavior.

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 short sentences ordered by importance: when to use, what comes back, what it will not do. Every clause carries information an agent needs, and there is no filler or repetition of the title.

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?

With no parameters, no output schema and a read-only annotation profile, the description carries the whole burden and does so: it lists the returned fields in place of an output schema and draws the boundary around document and payment actions. Nothing needed to select or call this tool correctly 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?

The tool takes zero parameters, so there is no schema semantics to add; the description correctly says nothing about inputs. Baseline for a parameterless tool is 4.

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 ("Lists the account's applications") and enumerates exactly what each entry contains: reference such as #1017, visa type, applicant count, current stage, start date. That field list also implicitly separates it from application_status, which covers a single application's status.

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 their own Spain Visa Submit applications" gives an explicit inclusion condition and a scope restriction. It also rules out adjacent intents by saying uploads, payment and power of attorney happen only on spainvisasubmit.com, though it never names a sibling tool as the alternative for single-application or non-owned queries.

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