fetch_page

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

With no annotations, the description carries the full behavioral burden. 'Inicia sesión por web' discloses that the tool authenticates via a web session, and 'devuelve el texto visible' clarifies that it returns rendered visible text, not structured data. It lacks caveats about session state, rate limits, or side effects, preventing a 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?

One sentence that front-loads the action and output, with a parenthetical that efficiently adds use-case context. There is no filler or repetition, and every component contributes to tool selection and invocation.

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 tool with one required string parameter and an existing output schema, the description covers the core behavior and intended use cases well. It is only slightly incomplete in not mentioning URL format expectations or potential web-login failure modes, but it is sufficient for an agent to call it correctly in most scenarios.

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 input schema provides only a bare string 'url' with 0% description coverage. The description compensates by indicating the URL must target a page in the virtual classroom and gives typical page types (foros, calificaciones, avisos). It does not clarify whether relative or absolute URLs are required, but it meaningfully constrains the parameter.

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 names a specific verb and resource ('devuelve el texto visible de cualquier página del aula virtual') and explicitly distinguishes the tool from the API-based siblings by stating it is useful 'para lo que la API no cubre'. This makes its role as a web-scraping fallback clear.

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 strong contextual guidance: use the tool when the API does not cover something, with concrete examples (foros, calificaciones, avisos). However, it does not explicitly name sibling alternatives or state a positive when-not-to-use condition, so a point is held back.

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