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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context beyond that: the result set is a fixed enumeration of exactly seven items, and each item carries a page identifier with a predictable acm-<code>.ai naming pattern — useful for a follow-up get_signal call. It stops short of saying whether this is a static snapshot or refreshed data, and the fragmentary phrasing leaves the 'returns a list' action implicit.

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 compact sentence with no filler, and the key content (the seven signals, their meaning, their page codes) is front-loaded. It is a noun-phrase fragment rather than a full statement of action, which slightly weakens immediate comprehension.

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 zero-parameter, read-only list tool with no output schema, the description covers what matters: how many entries come back, what fields each entry has, and the page-code format. The only real gap is the relationship to get_signal, which the agent must infer from the naming convention.

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?

The tool takes no parameters, so the baseline is 4 and there is nothing for the description to compensate for. The description correctly implies no filtering or input is needed to get the full set.

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 concrete resource (the seven ACM-68000 signals) and states exactly what each entry contains: the signal's meaning for a listed issuer and its page filename (acm-<code>.ai). The fixed cardinality of seven plus the page-reference detail makes the tool's output identifiable at a glance. It does not explicitly contrast itself with the get_signal sibling, so it lands at 4 rather than 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 only implied: by describing the complete set of seven signals and their codes, the description hints this is the catalogue-lookup step. It never states when to call this versus get_signal (e.g., 'call this first to discover codes, then use get_signal'), and offers no exclusions or prerequisites. An agent can infer the intent but must do the routing work itself.

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