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

Adds substantive traits beyond the readOnly/idempotent annotations: 'Computes nothing: every figure and date is copied whole from a stored value, and the response holds no JSON number' and 'No overall verdict, score, grade or count of strong links: live charities get no worked/didn't-work word.' It also declares the degraded case (covered: false, all links 'Not covered'), which an agent needs to interpret a partial result.

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 purpose is front-loaded, but the middle is a long run-on enumeration of output fields in a single sentence, and the trailing 'Same function as GET /v1/verdict-chain/{org_id}' adds little for an MCP caller. The field list is defensible given no output schema, but the packaging makes it slower to parse than it needs to be.

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 must explain the return shape and does: links fields, weakest_link, open_questions, summary_donor_voice, rung_rules, widest_evidence_gap, better_source, covered. Combined with the no-numbers constraint and the uncovered-charity behavior, an agent has everything needed to call and interpret it.

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 coverage is 0%, so the description must carry org_id, and it only indirectly does so via 'for one charity' and 'Same function as GET /v1/verdict-chain/{org_id}'. It never states the org_ prefix format, that it must exist, or what happens with an unknown org_id — the schema pattern is the only source for that.

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 resource ('the verdict chain for one charity, link by link (L0 Defined to L7 Checked)') and a precise scope of source data ('the evidence-gap ledger, our outcome ledger, the evaluator figures... and the verdict procedure'). An agent can tell this apart from get_ledger_record or decision_brief from the sentence 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?

Usage is only implied — the description says what gets returned and notes the fallback behavior for charities without an evidence-gap entry (covered: false, pointer to get_org), which is useful routing. But it never states when to prefer this over siblings like decision_brief, compare_charities, or get_ledger_record, so the agent must infer.

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