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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds one genuine behavioral note – access is gated by visibility rules – but says nothing about what happens on denial, whether a token changes visibility, or what is returned. With annotations carrying the main burden, this partial addition lands at a 3.

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?

A single front-loaded sentence with no padding. Its brevity is appropriate structurally, though the terseness contributes to gaps elsewhere rather than being a defect of structure itself.

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?

With no output schema, no parameter descriptions, and no annotations beyond the safety hints, the description should explain the token parameter, what a visibility-gated failure looks like, and what a Space contains. None of that is present, leaving the agent under-equipped for a two-parameter read tool.

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 0% with two parameters, so the description carries the full burden and fails to. It never explains that spaceId is the required identifier or what the optional token parameter is for (auth? overriding visibility?). The parameter names alone are not sufficient semantics.

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?

"Read a Space" gives a specific verb and resource, which is better than restating the name. But the qualifier "when its visibility rules allow it" is vague and the description never distinguishes this from the many sibling readers like spaces_list_public or fathom_space. An agent knows roughly what it does but not how it relates to alternatives.

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 only usage signal is the conditional clause about visibility rules, which doesn't tell the agent when to pick this over spaces_list_public or how to determine whether visibility actually allows the read. No exclusions, no prerequisites, no routing to siblings.

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