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

With no annotations, the description carries the full burden. It discloses a key behavioral trait: 'Returns an SPL revoke tx to sign'—indicating the tool does not execute the revocation directly but provides a transaction for the user to sign. It also explains the effect ('removes the engine's delegate') and reassures about fund custody ('Your funds were never held by us'). This is more than a tautological restatement.

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 sentences, front-loaded with the main action, and every phrase adds value. No wordiness or repetition of schema details.

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 one-parameter tool with no output schema, the description adequately explains the return value ('SPL revoke tx to sign') and the net effect. It could be slightly more explicit about the context (e.g., that this is on Solana), but 'SPL' and 'USDC ATA' provide sufficient cues. The simplicity of the tool means less is needed.

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 100% (agent_id is described as 'Your registered agent_id.'). The description adds no additional detail about the parameter, so the baseline of 3 applies as the schema does the heavy lifting.

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 opens with the precise verb+resource combination: 'Revoke the Entry Vault allowance.' It further clarifies the effect ('removes the engine's delegate on your USDC ATA') and clearly differentiates from the sibling tool 'enroll_entry_vault' by the verb 'Revoke'.

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 implied: if you want to revoke the Entry Vault allowance, this is the tool. However, there is no explicit statement of when to use it versus alternatives like enroll_entry_vault, nor any exclusions or prerequisites mentioned.

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