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

Annotations supply only the title (WRITE) and destructiveHint=true, so the description usefully confirms the HTTP verb (POST /api/v2/patients) and that a system-generated particle_patient_id is returned. It stops short of the behaviors that matter for a registration mutation: duplicate-patient handling, idempotency, permission/consent requirements, and rate limits.

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 compact sentences with the warning marker front-loaded ahead of the core action, and the return-value note placed immediately after. The endpoint line is slightly redundant but still earns its place as an implementation cue.

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 13-parameter write tool with no output schema, the description adequately signals the result shape (patient object plus particle_patient_id). It leaves gaps around failure modes, deduplication, and required consent, which an agent invoking a registration endpoint would benefit from knowing.

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% across all 13 parameters, so the schema already documents each field, its enum, and the date format. The description adds no parameter-level meaning (e.g., which fields drive demographic match quality beyond the ssn note in the schema), so the baseline 3 applies.

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 ('register a new patient with Particle Health') and flags it as a write. It implicitly distinguishes itself from the read-oriented siblings like particle_get_patient and particle_search_patient by tying the returned ID to 'subsequent queries,' but never names those alternatives directly.

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 conveys when to use it (registering a brand-new patient) and gives a follow-up tip about reusing particle_patient_id. However, there is no guidance on what to do if the patient already exists, whether to search first to avoid duplicates, or any prerequisites such as the data-sharing agreement referenced in the consent parameter.

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