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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds useful context the annotations cannot carry: the material is practice-reviewed educational content, not clinical advice, and results include review dates so freshness is assessable. No rate limits or failure behavior are mentioned, 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 sentences with zero filler: scope first, then return shape, then usage condition. Every clause carries information an agent would otherwise have to guess.

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?

There is no output schema, but the description enumerates the returned fields (titles, summaries, URLs, review dates), which is exactly what an output schema would otherwise provide. With only two fully documented parameters and annotations covering the safety profile, nothing needed to invoke the tool correctly 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%, and the schema itself gives the query format examples and the 1-10 limit with a default of 5. The description adds nothing about parameters beyond what the schema supplies, 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 (Search) and a well-scoped resource (Foundations' Healing Library of mental health articles), and further qualifies the content as practice-reviewed general education rather than clinical advice. The sibling tools are all practice-logistics tools (fees, counselors, locations), so there is no ambiguity to resolve and the agent can route correctly on name alone.

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?

"Use for informational questions where a reviewed article helps" gives a clear when-to-use condition and the parenthetical exclusion of clinical advice sets a boundary. It stops short of naming an alternative tool or stating when this should not be used (e.g., scheduling or crisis handling), which keeps it below a 5.

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