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

Beyond the readOnly/destructive annotations, it discloses a lot: fail-closed enforcement on every action, the on-chain spend cap being the hard limit, the need to fund the minted session key, base58 case-SENSITIVE allowlist matching, and the Bearer JWT auth requirement. On Solana it explains the session keypair mint and returned session_address — rich behavioral context that annotations do not carry.

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?

It is dense and clause-heavy, but front-loaded with the core action ('Step 2: authorize an actor...') and every sentence earns its place by adding a distinct operational fact (auth, funding, standing mandates). Slightly overstated with all-caps emphasis, but not padded.

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 12-parameter mutation tool with no output schema, the description covers authentication, the Solana-specific return value (session_address), funding expectations, and mandate lifetime semantics — everything an agent needs to call it correctly is present even without structured return documentation.

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 already 92%, so the baseline is 3; the description still adds real meaning, clarifying that target_allowlist entries are base58 addresses matched case-sensitively, that the session key balance is the spend cap for Solana, and how require_approval/no_expiry/expiry interact. It meaningfully raises understanding above the schema alone.

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 uses a specific verb+resource ('grant a scoped mandate' / 'authorize an actor to do specific actions within LIMITS') and situates itself in a workflow as 'Step 2', clearly downstream of signet_connect and complementing signet_revoke. An agent can distinguish it from the many signet_* siblings without opening the schema.

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 concrete decision rules: set require_approval=false for no-human execution, use no_expiry:true (or expires_in_days:0) for a STANDING per-wallet/per-chain mandate, and it notes revoke is available to undo. However, it stops short of explicitly contrasting with signet_action or other grant-adjacent siblings, so it is strong context rather than full when/when-not/alternatives coverage.

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