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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description contributes real behavioral context by disclosing the server-side ordering ('newest first, as Funraise returns them'), which an agent could not otherwise assume, but says nothing about auth, rate limits, or what a page of results contains beyond the records themselves.

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 short sentences with zero waste: what it lists, how it orders, how it filters, and the underlying endpoint. The most decision-relevant facts (resource and ordering) are front-loaded.

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 read-only, fully documented, 4-parameter list endpoint with annotations carrying the safety profile, the description covers what the agent needs to call it correctly. The remaining gap is the result shape (fields returned per supporter, whether totals/paging metadata come back), which matters somewhat given there is no output schema.

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 each parameter is documented in detail, including the paging 0-vs-1 ambiguity, so the baseline of 3 applies. The description restates the email and last_hours semantics and adds only the ordering guarantee, which marginally exceeds the schema.

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 (list supporters/donors in the Funraise CRM) plus the ordering ('newest first as Funraise returns them') and the two filtering modes. An agent can immediately tell this is a collection read, distinct from funraise_get_supporter or the create/note siblings.

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?

The two filter modes (exact email, last N hours) imply lookup-by-email and incremental-sync use cases, so usage is reasonably inferable. However, it never names an alternative or says when not to use this tool — notably it does not clarify when to prefer funraise_get_supporter for a single known supporter rather than an email filter here.

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