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

With no annotations, the description carries the full burden and does well: it discloses that despite the name 'donate' no donation is recorded, that eligibility is validated, and it enumerates the returned payment fields (wallet_address, amount, network, currency). It omits what happens when a campaign is ineligible (error shape) and any auth or rate-limit constraints, so it falls short of a 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?

Four tight sentences, front-loaded with the flow position and the crucial non-recording caveat, then inputs, then return values, then the next step. Every sentence earns its place.

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?

No output schema exists, yet the description compensates by listing the returned payment fields, and it fully documents the two-step workflow an agent must follow. Nothing needed to invoke this correctly is missing.

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 description names the three required inputs but adds no meaning beyond the schema, which already documents campaign_id (full UUID, no abbreviation) and reasoning (public-facing, exclude restricted evidence). At 67% coverage the schema is doing the heavy lifting, so baseline 3 is appropriate.

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 (validates campaign eligibility and issues payment instructions) and explicitly scopes itself as 'Step 1 of the MCP donation flow' that 'does not record any donation yet.' This clearly separates it from confirm_donation, the sibling that completes the flow.

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?

Explicit sequencing: call this first, send the on-chain payment, then call confirm_donation with the same campaign_id, amount, reasoning plus the tx_hash. Both the when-to-use and the hand-off alternative are named, leaving nothing to inference.

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