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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the agent knows the safety profile. The description adds nothing beyond that — no note on what happens when the id is unknown, no visibility/tenant scoping, no mention of the returned payload.

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 short sentence with zero filler and the scope stated up front. It is arguably over-terse given the gaps elsewhere, which keeps it off a 5.

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 single-parameter read whose annotations cover safety and whose schema covers the parameter, the minimal definition is close to sufficient. However, nothing explains what a market_signal is or what a caller should expect back, leaving an agent with no basis for interpreting the result.

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 'id' parameter is documented in the schema itself. The description's 'by id' restates rather than enriches it — no format, source-of-id, or lookup-behavior detail is added, 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 ('Read') and resource ('market_signal') with the singular scope ('one ... by id'), which distinguishes it from market_signal_list by cardinality of access. It falls short of a 5 because it never names the sibling tools (list/create/update) that an agent must choose among.

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: 'one ... by id' suggests this is for fetching a single known signal rather than enumerating, and the presence of market_signal_list establishes the alternative. There is no explicit when-to-use or when-not-to-use statement, and no prerequisite guidance.

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