Get Vault File

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable behavioral detail beyond these: it explains the returned format (header with path, ref, sha, size), imposes a size limit (>500000 bytes returns error), and specifies error messages for missing files and directories. This goes beyond the annotation baseline, though it doesn't describe potential rate limits or exhaustive edge cases, which is acceptable for a read-only file fetch.

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?

The description is longer than average but highly structured: a one-sentence purpose, then separate 'Args', 'Returns', 'Examples', and 'Error Handling' sections. The most critical info (purpose and primary use case) is front-loaded, and every section adds distinct value. It is not rambling; it is comprehensive yet organized. Minor redundancy exists between the error handling and the 'Don't use when' note, but not enough to lower the score further.

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?

Without an output schema, the description fully explains the return format (raw text with a small header) and error cases (not found, directory, binary, oversized). It covers both required and optional parameters, provides examples, and names the relevant sibling tools. For a tool of this complexity, nothing essential is missing—an agent can call it correctly and interpret results without additional information.

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 coverage is 100% with descriptions for both 'path' and 'ref'. The description adds meaning beyond the schema by providing an example for path ('governance/CONSTITUTION.md'), clarifying that paths are relative to repo root, and listing allowed ref values. This enriches the baseline of 3 for full schema coverage, making the parameters more intuitively usable.

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 states a specific verb-resource pair: 'Fetch the decoded text content of a single file from the canonical-vault repository'. It clearly distinguishes from siblings like vault_list_directory (which lists) and vault_search_files (which searches), and the scope is explicitly limited to a single file. This leaves no ambiguity about the operation.

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?

The description gives explicit when-to-use and when-not-to-use guidance. It provides concrete natural-language examples (e.g., 'Read me the current Constitution' → path='governance/CONSTITUTION.md') and directly tells the agent to use vault_list_directory for existence/size checks. It also covers the case of directories and binary files, routing them to the sibling. This is exemplary.

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