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

With no annotations, the description carries the burden. It does disclose valuable behavior: the return contents (typed distribution of labels, most-reinforced path, density, cold spots) and the read-time decay with ~69-day half-life. However, it omits access permissions, rate limits, and whether the operation is read-only (implied but not stated). The decay disclosure is genuinely useful; the rest leans on inference.

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?

Front-loaded with what the tool reads, then the return payload, then the decay caveat, then the usage trigger. Every sentence earns its place, though the return-value enumeration is dense and could be trimmed.

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 read tool with no output schema, the description compensates well by enumerating the return payload (label distribution, reinforced paths, density, cold spots) and the read-time decay behavior. It is nearly complete; only permission/rate-limit context is absent, which is minor for this domain.

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%, so the schema already fully documents id, intent, and radius. The description adds no parameter syntax or format details beyond what the schema provides, so the baseline 3 is correct.

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 (aggregate trace pattern for a piece or region) and explicitly distinguishes itself from the sibling 'navigate' — 'same trace data navigate shows individually, read at aggregate resolution.' This sibling differentiation is exactly what earns a 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?

Provides a clear when-to-use trigger: 'Use when you want to know what kinds of thinking this region of the graph has been productive for, before deciding which way to go.' It names the sibling navigate as the granular alternative but does not explicitly state when NOT to use this tool (e.g., when you want individual traces, use navigate).

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