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

Annotations already establish readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so the safety profile is fully covered by structured fields. The description adds useful context about what the payload contains (including 'current starting prices', signalling volatility), but says nothing about freshness guarantees, currency handling, or response shape. That is reasonable but not rich.

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 with a well-chosen colon list; every item earns its place. Slight cost is the lack of an explicit verb at the start, but nothing is padded.

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 telling the agent what comes back, and it does so by enumerating the content categories. Missing only minor details such as currency or link format, which are unlikely to change tool selection for a low-complexity, single-optional-param info tool.

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% and the single region parameter is fully documented in the schema with its enum values, so the baseline is 3. The description's mention of 'per region' and 'regions/languages' loosely maps to the parameter but adds no filtering semantics beyond what the schema already states.

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?

The description enumerates the specific content the tool returns (regions/languages, therapist counts, session format, per-region starting prices, browse/quiz links), which is far more informative than the title alone. The verb is implicit rather than stated ('How Pleso works: ...'), and it never explicitly says 'returns this information', but the resource is unmistakable and clearly distinct from search_therapists or get_therapist_profile.

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 only implied: an agent can infer this is the orientation/pricing lookup to call before recommending therapy. There is no explicit when-to-use statement, no exclusion, and no sibling named even though search_therapists and get_therapist_profile are obvious alternatives that the mentioned 'links to browse therapists' gestures at without routing to.

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