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

Annotations already declare readOnlyHint, destructiveHint, openWorldHint, and idempotentHint, so the safety profile is covered structurally. The description goes beyond by explaining the source of the data ('bundled, human-verified data', 'makes no network calls') and by enforcing a non-medical scope with a redirect policy, though the trailing hint restatements largely duplicate the annotation block.

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?

The opening sentence and the 'call this first' routing rule are front-loaded and earn their place, but the final two sentences re-explain readOnlyHint and destructiveHint and openWorldHint at length, which the agent already has from annotations. That is redundant padding that dilutes the otherwise tight definition.

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 describing the return value and does so explicitly (three hubs, display names, guide/resource counts). Combined with the routing rule and scope limits, an agent has everything needed to call it correctly.

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?

The tool takes no parameters, so there is no per-argument semantics to supply; the baseline for a zero-parameter tool is 4. The description correctly implies the tool is called without input and its output is fed into subsequent tools.

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 and enumerates the exact contents returned: 'the three InWithYou condition hubs (MS, Parkinson's, Alzheimer's/dementia) with display names and guide/resource counts.' An agent immediately knows what this tool yields, distinct from find_guides or match_resources.

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 an explicit sequencing rule ('Call this first when the user's condition is unclear, then pass the chosen condition to every other tool') plus clear when-not boundaries ('Never use for diagnosis, treatment advice, drug information, or symptom interpretation') and a redirect instruction.

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