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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the description's main added value is the note that calling it 'no cuenta como lectura de ninguna nota' — a non-obvious side-effect clarification. It also defines the universe it inspects (whole brain graph, including broken links), which goes beyond the annotation. It stops short of saying how results are ordered beyond the limit hint or whether the graph is computed live vs cached.

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-loads what the tool returns before moving to alternatives and usage triggers, and every clause carries information (definitions, routing, next step). It is dense but slightly overloaded with three semicolon-separated usage cues in one sentence, which costs a little readability.

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 read-only, zero-required-param tool with no output schema, the description covers what is returned conceptually (three categories) plus exclusions and follow-ups, which is ample. The only gap is that it does not clarify that `limit` applies solely to the central-notes list, a detail left entirely to the schema.

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 100% and the single 'limit' parameter is fully documented in the schema (1-50, default 10, controls how many central notes). The description never mentions limit at all, so it adds no meaning beyond the schema — baseline 3 applies for a well-covered 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?

States a specific verb and resource ('Mira el grafo del cerebro') and immediately enumerates the three things returned: central notes, orphans with no in- or out-links, and broken links. The parenthetical definitions ('más vecinos distintos', 'sin ningún enlace, ni de entrada ni de salida') remove any ambiguity about what counts as central vs orphan, so an agent can distinguish it from brain_health without opening a schema.

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?

Explicitly routes between tools: content-level review (tensiones, notas sueltas) belongs to brain_health, whereas this one answers isolation/centrality/where-to-connect questions. It even names the follow-up action for the orphan case ('candidatas a enlazar con search_brain'), giving both when-to-use and what-to-do-next.

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