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

Annotations only say this is a non-read, non-destructive mutation; the description adds real value on top by disclosing the plan-based client cap and its HTTP 426 signal, plus the POST /clients.json endpoint. It omits duplicate-email behavior and permission requirements, keeping it below 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 tight sentences with the WRITE marker and required fields front-loaded. The trailing endpoint string (POST /clients.json) earns little for an agent that already has the tool binding, but it costs only a few tokens.

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 15-parameter mutation with a nested object and no output schema, the description covers required fields and the quota error but says nothing about what comes back (e.g. the new client id) that the agent would need for follow-up calls. Adequate to invoke correctly, incomplete for the surrounding workflow.

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 coverage is only 40% across 15 parameters, so the description must compensate — and it partly does by naming the three required fields and clarifying that a company name goes in `name` (resolving a real ambiguity in the schema's "full name or company name"). The other ~10 fields, including the nested other_contact object, get no description-level treatment.

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 ("create a client in Bidsketch") with a leading WRITE marker, which cleanly separates it from the get/list/update siblings. It stops short of naming those siblings explicitly, so a 4 rather than a 5.

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 clear operational context: it is a write, the three required fields are named, and the plan-cap constraint (HTTP 426) tells the agent what failure to expect. It does not state a when-not condition or route to bidsketch_update_client / bidsketch_list_clients, so no exclusions are provided.

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