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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is partly covered. The description adds genuinely new behavioral context the annotations cannot express: the two hard failure windows (post-entry-price and the 5-minute pre-open blackout). It does not mention auth requirements or whether the deletion is irreversible, so it falls just short of a 5.

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?

One sentence carries the action, the precondition, the example, the two exclusion windows, and the alternative tool. The operative constraint is front-loaded and every clause 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?

For a one-parameter destructive tool with an output schema absent but unnecessary, the description covers the decisive question of when the call will fail. Only minor gaps remain, such as whether the cancellation is permanent or what state the signal is left in.

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% and the single signal_id parameter is already documented with its source ('from publish_signal or list_my_signals'). The description adds no format, constraint, or sourcing detail beyond the schema, so the baseline 3 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 and resource ('Delete one of your signals') and immediately bounds it with the precondition 'before it executes'. It explicitly contrasts itself with the sibling close_signal, so an agent can route between the two without opening either 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?

Gives when-to-use (signal has no entry price yet, e.g. published after hours), when-not (once it has an entry price, or in the 5 minutes before market open), and the named alternative (close_signal for executed signals). Nothing is left to inference.

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