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

The only behavioral content is the REST path GET /contacts/{id}, which restates readOnlyHint=true rather than adding to it. Nothing is said about error behavior for missing IDs, permission requirements, or what 'in full' returns.

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?

Two short fragments, front-loaded and waste-free. It is arguably over-compressed, but conciseness itself is good.

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 one-parameter read-only lookup with annotations covering safety, the definition is minimally sufficient. However, with no output schema, the agent has no idea what 'in full' actually includes.

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 contact_id is fully documented in the schema itself. The description adds no syntax or meaning beyond that, making the baseline 3 correct.

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 (get a contact) and clarifies scope with 'One contact in full', which distinguishes it from a bulk list. It never names the sibling splose_list_contacts, so differentiation is implied rather than explicit.

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?

There is no when-to-use statement, no prerequisites, and no alternative named. The agent must infer from 'one contact' that list_contacts is the bulk alternative rather than being told.

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