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

Annotations already establish readOnly=true, destructive=false, and closed-world, so the safety profile is covered. The description adds a genuinely non-structured disclosure — that the output is aggregate participation data and cannot substantiate savings claims — which prevents a common misinterpretation. It still omits aggregation window and return shape.

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?

Two short sentences, front-loaded with the core action and followed by the one caveat that matters. No filler, no repetition of the name or of annotation-declared safety properties.

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 zero-param, read-only tool this is roughly adequate, but with no output schema the description carries the burden of explaining return values and it does not — 'participation counts' is undefined as to units, time window, or breakdown dimensions. An agent knows the tool's purpose and one caveat, but not what it will actually receive.

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 zero parameters, so there is nothing for the description to disambiguate; baseline for a 0-param schema is 4. The description correctly implies the tool is unfiltered and returns a global aggregate rather than requiring scoping arguments.

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 — 'Read aggregate participation counts' — so an agent knows it retrieves summary statistics rather than records. It does not, however, explicitly distinguish itself from siblings like exchange_search or exchange_discover, leaving the agent to infer that 'stats' means aggregates.

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 line 'Reports do not prove cost or energy savings' functions as a when-not-to-rely-on-this caveat, which is useful guidance. But there is no positive statement of when to use this tool versus exchange_search or exchange_discover, and no prerequisites are named.

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