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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world, non-idempotent), so the description only needs to add context — and it does, disclosing a payment_required failure mode and the required agent behavior (inform the operator, do not retry). It stops short of describing result shape or what happens with an under-specified query, so it is not a full 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?

The usage condition is front-loaded and the paywall instruction is isolated in its own short paragraph, so both are easy to scan. Slight redundancy between the opening example list and the closing 'prefer a specific site, company or period' sentence, but nothing is wasted overall.

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 two-parameter read-only tool with no output schema, the description covers selection, prerequisites, and the payment failure path, which is most of what an agent needs. It is still incomplete on the two things it uniquely must supply: the expected form of 'query' and the role of 'sessionId'.

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 0%, so the description must carry the parameter burden, and it largely does not. It hints at what 'query' should contain (site, company, period) but never says whether it is natural language or structured, and the second parameter 'sessionId' is never mentioned at all.

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 action and resource: answering a specific question about verified oil-and-gas emissions data, with concrete examples (methane, site/company/period) and standard names (PPDM, OGMP 2.0). It also explicitly contrasts itself with semantic_templates and with general climate questions, so an agent can route correctly without opening the schema.

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 when-to-use condition, an explicit when-not ('Do not use for general climate questions'), and a prerequisite/alternative ('Call semantic_templates first'). It also adds a query-refinement instruction ('Prefer a specific site, company or period') that steers call quality.

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