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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered structurally. The description adds value beyond that by flagging medical, doctor_details and additional_needs as sensitive fields gated behind an opt-in flag, and by naming the underlying endpoint (GET /children/children/{id}). It does not discuss permission scope or error behavior, 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?

Three short sentences, front-loaded with what the call returns, then the sensitive-field caveat, then the endpoint. No filler and nothing that duplicates structured data unnecessarily.

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?

With no output schema, the description carries the burden of describing the response and does so by enumerating the returned field groups, plus explicitly carving out the conditionally-returned medical fields. For a two-parameter single-record read whose annotations already cover the safety profile, nothing an agent needs is missing.

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 baseline is 3 and the schema already documents both params. The description goes slightly beyond the schema by emphasizing that medical fields are sensitive and are only surfaced via include_medical: true, reinforcing the opt-in semantics rather than merely restating them.

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 ('Get one child by id') and immediately enumerates the returned surface (names, DOB, school, contact details, custom fields, consents, sites, status), which is exactly what separates it from the sibling churchsuite_list_children. An agent can tell single-record retrieval from list retrieval without opening either 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?

The 'by id' framing makes the precondition clear (you must already have a child_id), and it gives an explicit conditional for the sensitive path: medical/additional-needs fields 'only with include_medical: true'. It stops short of naming the alternative ('use list_children to discover ids') or any when-not condition, so it is clear context rather than full routing guidance.

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