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

The description clearly describes a state-changing operation: a credit 'enters the book' and must pass verification before it can, and it is paired with a sibling called delist_credit that reverses it. Annotations declare readOnlyHint=true and destructiveHint=false, which directly conflicts with that. An agent relying on the annotation would treat a write as a safe read.

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 sentences with no filler, and the hard prerequisite is front-loaded ahead of the optional registry path. The only small cost is that the first sentence carries the ambiguous 'list' framing that the rest of the text has to repair.

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?

An output schema exists, so return values needn't be described, and the verification prerequisite plus the Verra path are well covered. For a state-changing tool with contradictory annotations, though, it omits what an agent most needs: whether listing is reversible and how, duplicate-listing behavior, and any permission or identity requirement tied to issuer.

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% across 10 parameters, so the description carries the load and partially does: verification_ref is explained as a D-Score/land-verification attestation, and registry/vcs_project_id/serial_number/vintage/methodology are tied to the Verra cross-reference flow. However, issuer, project_id, mass_g and especially price_minor_per_kg (minor units per kg is not obvious) are left undocumented, so several required parameters remain cryptic.

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?

The description says 'List a conservation credit on the book,' which names a resource but uses 'list' — a verb that reads as enumeration in most MCP catalogs while here it means creating a sell-side listing. Phrases like 'unverified credits cannot enter the book' and the sibling delist_credit disambiguate it, but the agent must do that inference. It never explicitly contrasts itself with delist_credit or the buy_offset family.

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?

It gives real conditional guidance: verification_ref is stated as REQUIRED with the consequence ('unverified credits cannot enter the book'), and it names the exact condition and parameter for the Verra path ('To trade on the Verra network, pass registry="verra"' plus the VCS provenance fields). What's missing is any when-not-to-use guidance or routing to delist_credit/buy_offset.

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