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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false). The description adds genuine behavioral context beyond them: idempotent semantics ('Si ya existe, la deja como está y la devuelve') and that the existing record is returned. It does not state permissions or full return shape, so not 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?

Front-loads the core purpose, then idempotency, then the alternative, then the type glossary. The bulleted type list is long but earns its place since the schema enum names alone are unexplained. Slightly verbose but no wasted flourishes.

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 4-parameter mutation tool with an output-less schema, the description covers purpose, idempotency, sibling routing, and enum semantics, which is close to complete. Minor gaps remain around permission requirements and what exactly 'la devuelve' returns, but nothing critical for correct invocation.

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%, so baseline is 3, but the description adds meaning the schema lacks by explaining each relation_type enum value (hierarchy, holding, org, area, subarea, team, client, partner) with example semantics. This meaningfully enriches the otherwise opaque enum.

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+resource ('Crea una relación entre dos entidades del Atlas') and explicitly distinguishes itself from the sibling change_entity_relation_type for the type-changing case. An agent can tell it apart without opening any 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?

Gives an explicit alternative and condition: if the relation already exists it is left unchanged, and to change its type use change_entity_relation_type. It lacks general when-to-use/when-not context (e.g. prerequisites that both entities must exist), so it falls just short of 5.

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