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

With readOnlyHint=true already declaring a safe read, the description adds that profiles are limited to verified therapists and that registration numbers are publicly displayed, which is useful scoping. It does not cover failure behavior (invalid/unknown slug) or that results are a single object rather than a list.

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?

A single front-loaded sentence that identifies the resource first and appends the slug definition and return contents. Every clause carries information, though the registration-number clause is slightly dense.

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 tool with no output schema, the description covers the resource, the parameter's origin, and the shape of the return (bio, credentials, registration numbers). Only error/empty-result behavior is left unspecified.

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 100% so the baseline is 3, but the description genuinely adds meaning by defining the slug as the last path segment of a profile_url, beyond the schema's terse example. This tells the agent how to obtain and format the value.

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 ('Full public profile of one verified therapist') and scopes it to a lookup by profile slug, which clearly separates it from the sibling search_therapists and list_filter_options. It does not name those siblings explicitly, so it stops short of the top mark.

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?

Usage is implied rather than stated: the parenthetical 'the last path segment of a profile_url' tells the agent where the slug comes from, which weakly signals when this tool applies. There is no explicit when/when-not or comparison against search_therapists if the caller lacks a slug.

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