Get a contact profile, or list them

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, so the safety profile is fully covered. The description adds useful behavioral detail beyond annotations: id omission switches to list mode, pagination behavior is implied by 'lists the account's profiles filtered by type and role', and it hints at preconditions for related save operations. This is strong but not exceptional—there is no explicit mention of open-world listing behavior or output format details, though the output schema covers return values.

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 sentences with zero filler. The first sentence front-loads the core behavior (get by id vs list), and the second sentence gives actionable guidance for sibling tools. Every sentence adds useful information and the definition remains compact.

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?

Despite a 10-parameter schema, the description is sufficient because the schema covers all parameter semantics at 100% and the output schema exists for return values. The description supplies the missing context: which sibling tools to use first/next, and the id-vs-list mode distinction. A 5 would require explicit pagination guidance or open-world caveats, but those are minor given the schema and annotations.

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 the schema already documents every parameter. The description adds a small amount of meaning by tying id omission to list mode and mentioning the field-type/role filters in the tool purpose, but it does not materially expand on the parameter meanings beyond the schema. Baseline 3 is appropriate because the schema carries the heavy lifting and the description only lightly reinforces it.

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 clearly states the tool returns one contact profile by id, or lists profiles filtered by type/role when id is omitted. It explicitly distinguishes itself from eurodns_contact_save_profile and eurodns_contact_set_as_default_profile, so an agent can select correctly among sibling contact tools.

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 provides explicit when-to-use guidance: read a profile before saving because save needs every field, and set_as_default_profile chooses which profile future orders use. This differentiates the read/list operation from mutating alternatives and gives the agent a clear procedural context.

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