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

Annotations already provide readOnlyHint=false and destructiveHint=false, so the safety profile is partly covered. The description usefully discloses the auth requirement (a Lit auth signature is needed) and states the return value, but says nothing about failure modes for non-Lit-encrypted bundles or any side effects. Adequate but thin for a cryptographic operation.

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 short sentences with zero redundancy; the action, the required input, and the return value are all front-loaded. 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?

With no output schema, the description correctly states what is returned (the decrypted bundle payload), and both parameters are fully documented in the schema. The remaining gap is that error/edge behavior (e.g. wrong auth signature, non-encrypted bundle) is not addressed, though this is minor for a simple two-parameter tool.

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%, including a detailed nested authSig description, so the schema does the heavy lifting and the baseline is 3. The description only gestures at the two parameters (bundle + Lit auth signature) without adding format or constraint detail beyond the schema.

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 names a specific verb (Decrypt) and a precise resource (Lit Protocol-encrypted evidence bundle), which distinguishes it from read-style siblings like get_evidence_bundle. It does not explicitly reference any sibling by name, so an agent must infer the difference, keeping it just below a 5.

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: use this when you have a Lit-encrypted bundle and a Lit auth signature. There is no explicit when/when-not guidance, no mention of the alternative get_evidence_bundle for metadata, and no statement of what happens if the bundle is not Lit-encrypted. This is minimum-viable context.

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