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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds scope beyond that: what the returned payload includes (backlinks and link targets), and that non-Markdown assets are silently out of reach — a meaningful behavioral constraint. No permissions or rate-limit notes, but none are expected for a local read.

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 operation and its return payload, then the key parameter forms, then a scope exclusion. Every sentence carries distinct information; nothing is restated from the title.

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?

An output schema exists, yet the description still summarizes what comes back at a useful level of granularity. All three parameters are documented, the Markdown-only limitation is stated, and no ambiguity remains about vault selection (delegated to obsidian_list_vaults in the schema).

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%, so the baseline would be 3; the description earns above baseline by giving concrete accepted forms for `note` ('Projects/Plan.md', or a wikilink-style name like 'Plan'), which resolves real ambiguity about path vs. name syntax. It does not touch `vault` or `max_bytes`, which the schema already documents well.

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?

Names a specific verb and resource ('Reads one note of an Obsidian vault') and enumerates exactly what the payload contains: text, frontmatter, tags, outgoing wikilinks with their targets, and backlinks. This is far more informative than a bare 'read note', though it never explicitly contrasts itself with obsidian_search_notes or obsidian_write_note.

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 third sentence gives a real exclusion ('Only Markdown notes are read: attachments and Obsidian's settings folder are not'), which prevents misuse attempts. It stops short of naming when to prefer obsidian_search_notes to locate a note first, so it is clear context without explicit alternatives.

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