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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuine behavioral value by disclosing what the operation returns (status, fee, programs invoked, balance deltas, last log lines) and implies log truncation. It stops short of covering error cases (invalid/unknown signature) or rate limits.

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?

A single tight sentence that front-loads the action and immediately lists the payoff fields. No filler, no repetition of the title.

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 carries the burden of describing returns and does so by listing the decoded fields, which is strong for such a simple read-only tool. It leaves error/edge behavior (bad signature, non-existent tx) unstated, so it falls just short of fully complete.

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?

There is one parameter and schema coverage is 100%, with the schema already specifying 'Transaction signature (base58)'. The description's 'Decode a transaction signature' adds no syntax or format meaning beyond the schema, so the baseline 3 for schema-carried semantics applies.

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 ('Decode') and resource ('transaction signature') and enumerates the returned fields (status, fee, programs, balance changes, log lines), which makes the scope clear. It does not explicitly distinguish itself from siblings check_token/inspect_wallet, but the resource is distinct enough to separate them.

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?

The description implies the trigger (you have a signature and want it decoded) but offers no explicit when-to-use, prerequisites, or routing against check_token or inspect_wallet. Comparable to the MID calibration example, which scored 2 for lacking when-to-use guidance.

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