repo_blast_radius

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

The description asserts 'Read-only, deterministic, zero side effects', but the annotations declare readOnlyHint=false, which signals the tool may mutate state. This is a direct contradiction between prose and structured metadata and is the most consequential thing an agent needs to resolve before calling.

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 the core semantic, then a when-to-use/when-not-to-use block and an output summary. Dense but each sentence carries routing or behavioral information; the output line earns its place since no output schema exists.

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 graph-analysis tool with no output schema, the description supplies the return shape (callers, subclasses, importers, cochange, summary), usage routing, and semantics. It would be complete were it not for the unresolved read-only claim, which leaves the tool's actual safety profile ambiguous.

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 node_id, limit, max_hops, and include_cochange are all documented in the schema with defaults and maxima. The description adds only loose framing (hop distance, co-edited files) and no format or syntax 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?

The description gives a precise verb+resource with scope: 'Reverse reachability from a node_id' enumerating callers, subclasses, importers, and co-edited files by hop distance. It is immediately distinguishable from siblings like repo_search and repo_read, which it names explicitly.

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?

Explicit when-to-use ('before editing a symbol', 'what is the blast radius of changing X') and when-NOT-to-use with named alternatives ('do not use for open-ended search (use repo_search) or to read a symbol's own body (use repo_read)'). This is exactly the routing guidance an agent needs.

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